Cant choose the intel i5 when picking nVidea?

[Saucepan]

Hello all.

When using the custom build PC option for gaming, it wont let me choose anything other than 3 variants of the intel i7 when I choose the nVidea/SLI. It'll let me choose the intel i5 when I pick AMD for graphics, but I want to get the 3GB 580 with intel i5.
I'm choosing these options: Build your own desktop > intel > Crossfire/SLI Gaming Computers > SLI Gaming Computers.
I've seen people posting their specs with the 580/i5 in it so is there a reason I cant choose it? Or am I missing something? Sorry if I'm being a newb.

Thanks

Edit: Nevermind I just found out I can edit a pre-made PC to have both. Weird I couldn't do that when selecting build your own.

 

[Usukane]

http://www.pcspecialist.co.uk/computers/intel-sandy-bridge-pc/

 

[PCS]

It's because the SLi gaming systems here: http://www.pcspecialist.co.uk/computers/intel-core-i7-pc/ use X58, not the Sandy Bridge chipset. To configure a Sandy bridge i5 based system, see here: http://www.pcspecialist.co.uk/computers/intel-sandy-bridge-pc/